<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
// 父页面
<iframe id="iframe" src="http://test.com/childrenCrossDomain.html" name="childrenName"></iframe>

<script>
    let iframe = document.getElementById('iframe');
    function sendToChildren(){
        iframe.contentWindow.postMessage('hello啊，在吗', 'http://192.168.100.26/')
    }
</script>
</body>
</html>
